- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 30 Aug 2016
Help develop this article - click 'Edit this article' above.
Tower cranes are usually supplied on a hire basis, with the client being responsible for the design and construction of the base upon which the crane will be erected. Details of loading are provided by the crane supplier and the base is most commonly designed as a temporary structure, although sometimes a crane base will be incorporated into the permanent structure to save on cost and time.
Loads are given in two forms, ‘in service’ loads, where the crane is functioning and wind speeds are restricted (ie cranes will not operate at high wind speeds), and ‘out of service’ loads, where the crane is not being used but maximum wind speeds may occur.
The location for a crane should be carefully selected to provide a maximum working radius, and when two cranes are being used on the same site mast heights and jib lengths must be considered so that they do not clash.
Cranes are typically structured around two rails at their base between 4.5m-10m apart with wheels in each corner. Cranes are not normally tied down, so sufficient kentledge must be provided to ensure vertical loading from the crane passes through the rails and into the foundation. The foundation is designed so that the unfactored loading from the crane and the unfactored loading from the foundation itself create a bearing pressure which is less than the allowable bearing pressure of the soil.
- Where possible a structural fill can be compacted and used to support a crane with the load spreading through layers of track support at 45° in to the soil strata below.
- When loads from the crane increase, reinforced concrete foundations may be required. This can involve a series of reinforced concrete beams used to support line loads as a result of the crane loading.
- When ground conditions are particularly poor, piled foundations may be necessary. Careful design is required to ensure that reinforcement at the top of the pile top does not cause problems for positioning the mast base section of the crane.
 Find out more
 Related articles on Designing Buildings Wiki
- Avoiding crane collapses.
- Bituminous mixing and laying plant.
- Compressed air plant.
- Concreting plant.
- Construction plant.
- Crane regulations.
- Deleterious materials.
- Design liability.
- Earth-moving plant.
- Excavating plant.
- Facade retention.
- Forklift truck.
- Health and Safety.
- Temporary works
- Trench support.
- Types of crane.
 External references
- BS5975:2008 + A1: 2001 Code of Practice for Temporary Works Procedures and the Permissible Stress Design of Falsework (BSI 2011).
Featured articles and news
When is there a right to light, and what happens if it is obstructed?
What would the nationalisation of economic infrastructure mean for GB?
A new guide to improving value by reducing design error.
We've reached 80,000 page views a day and 10,000 registered users. Why not join them?
A masterplan is a framework within which a location is encouraged to develop or change. Read our introductory article.
New consultation announced on a specialist Housing Court to settle landlord-tenant disputes.
ICE responds to a transport consultation advising the government to make decisions enabling more inclusive cities.
BRE and Loughborough University complete first phase refurbishment of demonstration home.
How the risk of collapse of fibrous plaster ceilings is being addressed in theatres.
If you’re a great writer and have practical experience of the construction industry, it could be you.
Frustrated by long documents or technical jargon? Put off by sign-up forms or costs? Take this 5 min survey to help improve construction knowledge.